Measuring health and frailty in wild insects
Grantee: Jelle Boonekamp
Institutions: University of Glasgow, United Kingdom
Grant amount: $63,536
Grant type: Ad hoc
Focal species: Field cricket (Gryllinae)
Conservation status: Least concern
Disciplines: Physiology, entomology
Research location: United Kingdom
Project summary
From an evolutionary perspective, health and well-being is best expressed in terms of fitness variation, the logic being that animals who are optimally adapted to their local environment should be healthy. Hence, health and fitness are intimately entwined on a conceptual level. Morphological, behavioral, and physiological traits that are predictive of fitness could provide potential biomarkers of health, and such approaches have been developed for many different wild vertebrate species. However, due to their small size and mobility, it has proven exceedingly challenging to follow individual insects longitudinally in the wild, let alone their descendants, to measure individual performance and fitness. Consequently, there is a paucity of literature on wild insect health and well-being.
The aim of this project is to address this knowledge gap by developing a non-invasive frailty index that measures the health of individual insects in their natural habitat and that can be applied across species. Analogizing to frailty indices used in human patients, this project will develop an insect frailty index using relevant traits applicable to many different insect species. In humans, the frailty index is highly predictive of morbidity and remaining life expectancy. Similarly, this project seeks to validate the insect frailty index against mortality and fitness data in an insect population by testing whether “frail” individuals have increased mortality risk and reduced fitness.
This project is made possible by the work that we have done to establish a long-term field study of a natural population of crickets (WildCrickets.org). Using a network of 140 video cameras, all the adults in the population are longitudinally monitored from their emergence in early spring to their natural death in late summer. All their movements, reproductive behaviors, fights, and predation events are recorded, and fitness is measured by genotyping and counting the number of surviving genetic descendants in the next year.
Why we funded this project
Willingness to investigate the welfare of insects is somewhat rare, as are creative ways to assess their welfare. This project both proposed a potentially usable metric, and has access to an unusually useful resource through the WildCrickets.org project. While any particular approach to assessing welfare in insects is unlikely to work, we are hoping to seed enough approaches and strategies that others take up the call, eventually drawing in enough different approaches to produce usable strategies for assessing insect welfare in the wild. Finally, because many of the project resources were already acquired through other sources, we were to fund exclusively the welfare-focused aspects of the project.
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